Field of the Invention
Preferred example relates to the art of a selectable one-way clutch adapted to selectively enable torque transmission only in one direction and to interrupt torque transmission in both directions.
Discussion of the Related Art
A selectable one-way clutch is brought into engagement mode by bringing struts held on a pocket plate into engagement with notches formed in a notch plate, and into disengagement mode by rotating a selector plate interposed between the pocket plate and the notch plate in such a manner to push the struts into the pocket of the pocket plate. In the prior art, lubrication device for the selectable one-way clutch have been proposed to prevent malfunction caused by friction acting between the rotary plates.
For example, JP-A-2003-021220 describes a device for delivering oil between a notch plate and a stator. To this end, according to the teachings of JP-A-2003-021220, the stator is provided with a recess formed on a pocket of a stator body, and oil passages connected to the recess.
JP-A-2007-016914 also describes a lubricating structure for a one-way clutch adapted to deliver oil to a roller selectively providing engagement between an inner race and an outer race so as to limit damage of the roller. According to the teachings of JP-A-2007-016914, specifically, oil is delivered to the roller through a lubrication passage extending in the inner race obliquely with respect to a rotational axis of the inner race, and with respect to a rotational axis of the roller as seen from an outer circumference side of the inner race.
In the conventional selectable one-way clutches, lubrication oil remaining in a lower section is sprinkled to the rotary members by the notch plate. In the selectable one-way clutches thus structured, however, struts of the lower section may be delayed to be pushed up by viscosity of the oil remaining in the lower section. In the conventional selectable one-way clutches, therefore, only the strut in an upper section of the selectable one-way clutch that is not soaked in the oil would be brought into engagement with the notch, and hence the strut thus brought into engagement with the notch earlier than the other struts and notches may be subjected to an engagement load excessively.